The present invention relates to accessing information recorded on an optical disc, and more particularly, to a method of accessing system lead-in information on an optical disc by moving an optical pick-up unit to a system lead-in area before the tracking servo is enabled or the disc type is identified, and related information reproducing apparatus thereof.
Optical disc has become a popular storage medium today. An information reproducing apparatus therefore is designed to read data from or record data onto a loaded optical disc. In general, a servo system is implemented to control tracking and focusing of an optical pick-up unit when accessing the optical disc. Generally speaking, the parameters of the tracking servo control and the focusing servo control should be properly set to have optimum data accessing performance. However, if the parameters are not accurately initialized before enabling the tracking servo control and the focusing servo control, the servo system or the read channel might become unstable. Taking the HD-DVD disc for example, a lot of information is recorded in a system lead-in area, such as the book type (disc type), mark polarity (high-to-low disc or low-to-high disc), burst cutting area (BCA) flag, track shape, disc code (disc manufacturer ID), etc. In a case where the mark polarity is erroneously determined, the stability of the servo system and the read channel is not guaranteed. Therefore, a novel mechanism of reading the system lead-in information for adequately initializing servo parameters set to the tracking servo and/or the focusing servo is required to improve the data accessing performance.